lanthanum

A sibling comment [1] cited additional details that the find is indeed mostly cerium, followed by lanthanum which also has limited economic value.

Over half of it is cerium and most of the rest is lanthanum.

NiMH batteries require Cerium, Lanthanum and Neodymium, but those batteries are not used in BEVs at all anymore.

Lead is less abundant in the Earth's crust than cobalt or neodymium, or even lanthanum.

Most of the economic value is in the elements that are not cerium or lanthanum.

The other half is neither rare, nor particularly expensive The three most important rare earth elements are lanthanum, neodymium and praseodymium.

Rare earths are elements like lanthanum or ytterbium.

> These batteries in the first generation of hybrid vehicles contained about ten kilos of lanthanum, which is a rare earth.

'High' temperature super conductors were only recently discovered, and only a couple of years ago lanthanum decahydride was shown to transition at -10F.

Why are rhenium, rhodium, lanthanum, europium, dysprosium, thulium, ytterbium, yttrium, strontium, thallium, magnesium and manganese so irreplacable?

It did give me some pretty good ideas, though: - Nitrates (of magnesium, calcium, yttrium, lanthanum, etc.) are good precursors for metal oxides for bonding ceramics, and have special virtues for SHS.

As far as I can tell this paper isn't making any extraordinary claims about extraterrestrial intelligence [2] (which Loeb is infamous for), it's just confirming that the chemical composition - the ratio of beryllium, lanthanum, and uranium specifically - doesn't match any known minerals or alloys in our solar system.

From wikipedia: "Monazite is a reddish-brown phosphate mineral containing rare earth metals and is an important source of thorium, lanthanum, and cerium.

The last chemistry to use rare earths at scale was NiMH, the "M"(metal) being Lanthanum - also used in catalysts in the oil industry.

I guess part of the reason is that the "M" in "NiMH" stands for Lanthanum - a rare earth element which happens to be used in catalysts facilitating oil refinement.

Lanthanum or some other elements are often added to raise the melting point somewhat.) The electrodes aren't very big, but the density is definitely weird.

Lanthanum cobaltite for example has transition from diamagnet to paramagnet, likely due to change of spin state (see, e.g., [1]).

We know the first f orbital we see has size 4 -- it is the outermost orbital of Lanthanum.